Postfix: The Definitive Guide

Kyle D. Dent

If you're just running Postfix to do mail delivery from a desktop machine,
you really don't need any additional documentation — and Postfix
configuration is sufficiently simple that you can set up and configure
a real mail server without a book. If you want to know more about how
Postfix works, however, because you're doing something more complex,
because you want to know more about what's actually happening, or simply
from curiosity, then Dent's Definitive Guide is an excellent resource.
It is clearly written and easy to use.

Dent begins with some background on Postfix and its philosophy, and
on email, SMTP and Unix more broadly. Two chapters then cover the
basics in some thirty pages: one describes the Postfix architecture and
another its configuration and administration. There follow chapters on
management of the Postfix queue, basic DNS for email, local delivery —
mbox and maildir formats and POP/IMAP options — hosting multiple domains,
and mail relaying.

The remaining chapters cover more specialised topics. There's a
chapter on running mailing lists, covering simple :include lists
managed by Postfix itself, majordomo, and mailman. There's a chapter
on Postfix's extensive built-in spam controls and another on interfacing
to external content-filtering software. And there are chapters on SASL
authentication, TLS, and using an external database such as MySQL or LDAP.

How useful this material is obviously depends on what you want to do.
I wish I'd had the section on getting mailman to work with Postfix back
when I did that. And I found the chapter on spam controls most helpful,
using it to rewrite my anti-spam configuration completely. But I only
glanced at the chapters on SASL, TSL, and databases.

The Definitive Guide provides examples, but not much in the way of
step-by-step recipes — for those it's probably better to look online for
one which matches your operating system and setup exactly. What Dent's
book will give you is the background necessary to understand what's in
the recipes, or to experiment yourself.